(of characters in literature or drama) evoking empathic or sympathetic feelings
"Appealing" also means "able to attract interest or draw favorable attention"--both definitions fit because Julia is in pain on the floor and appealing to Winston for help, but she had deliberately fallen in front of him to get his attention and slip him a note. Compare with the definition and situation for "alluring" in the list for Part 1: Chapters 5-8.
Her eyes were fixed on his, with an appealing expression that looked more like fear than pain.
something serving to conceal plans; a fictitious reason that is concocted in order to conceal the real reason
If she had worked in the Records Department it might have been comparatively simple, but he had only a very dim idea whereabouts in the building the Fiction Department lay, and he had no pretext for going there.
of a quantity that can fulfill a need or requirement but without being abundant
If he could get her at a table by herself, somewhere in the middle of the room, not too near the telescreens, and with a sufficient buzz of conversation all round— if these conditions endured for, say, thirty seconds, it might be possible to exchange a few words.
His whole mind and body seemed to be afflicted with an unbearable sensitivity, a sort of transparency, which made every movement, every sound, every contact, every word that he had to speak or listen to, an agony.
"Ironical" also means "characterized by often poignant difference or incongruity between what is expected and what actually is"--this describes the situation that led to Julia's ironical smile: as an older man who'd separated from a cold wife, Winston would be expected to act more quickly when faced with a young woman who desires him. The novel was published in 1949, so there is additional irony in Julia being the one who starts and directs the affair.
She stood before him very upright, with a smile on her face that looked faintly ironical, as though she were wondering why he was so slow to act.
Compare with the verb "deride" and noun "contempt" in the list for Part 1: Chapters 1-4. Although both verbs connect to laughter ("deride" comes from the same Latin root as "ridicule"), they are emotionally focused on intense disrespect and dislike. Winston feels the same contempt Julia has for the Party, but he is uneasy about openly jeering. The only contempt he dares show is for Goldstein, whom the Party had set up for its members to deride.
Them, it appeared, meant the Party, and above all the Inner Party, about whom she talked with an open jeering hatred which made Winston feel uneasy, although he knew that they were safe here if they could be safe anywhere.
bending the head or body or knee as a sign of reverence or submission or shame or greeting
This bird is a wishful metaphor for Winston and Julia's relationship. Here's a more fitting metaphor: "The paperweight was the room he was in, and the coral was Julia’s life and his own, fixed in a sort of eternity at the heart of the crystal." But even that sounds too romantic and does not emphasize the contrasts between wings and weight, voluntary obeisance and forced obedience, the sun and a glass dome, musical variations and a fixed, hard, skeletal structure.
It spread out its wings, fitted them carefully into place again, ducked its head for a moment, as though making a sort of obeisance to the sun, and then began to pour forth a torrent of song.
technical skill or fluency or style exhibited by a virtuoso
The Latin "virtus" means "manliness" and "excellence" and is a root for both "virtue" and "virtuosity"--Winston admires the bird's virtuosity but also says, "I don’t want any virtue to exist anywhere." This might seem contradictory, but the bird exists outside the Party, while Winston must live within a society where virtue is not equated with excellence but with submission.
The music went on and on, minute after minute, with astonishing variations, never once repeating itself, almost as though the bird were deliberately showing off its virtuosity.
As they drifted down the crowded pavements, not quite abreast and never looking at one another, they carried on a curious, intermittent conversation which flicked on and off like the beams of a lighthouse, suddenly nipped into silence by the approach of a Party uniform or the proximity of a telescreen, then taken up again minutes later in the middle of a sentence, then abruptly cut short as they parted at the agreed spot, then continued almost without introduction on the following day.
He wondered vaguely how many others like her there might be in the younger generation—people who had grown up in the world of the Revolution, knowing nothing else, accepting the Party as something unalterable, like the sky, not rebelling against its authority but simply evading it, as a rabbit dodges a dog.
something that is emitted or radiated (as a gas or an odor or a light, etc.)
The smell was already filling the room, a rich hot smell which seemed like an emanation from his early childhood, but which one did occasionally meet with even now, blowing down a passageway before a door slammed, or diffusing itself mysteriously in a crowded street, sniffed for an instant and then lost again.
an urge to do or say something that might be better left undone or unsaid
The definition and the structure of the example sentence suggest that "compulsion" is an inner drive that can be acted upon or ignored. But what's intended here is a meaning that's closer to the verb "compel" ("force somebody to do something" or "to make necessary"). In Winston's experience, "compulsion" is an outside force that is always there, either in the form of a telescreen or of other Party members.
He wondered vaguely whether in the abolished past it had been a normal experience to lie in bed like this, in the cool of a summer evening, a man and a woman with no clothes on, making love when they chose, talking of what they chose, not feeling any compulsion to get up, simply lying there and listening to peaceful sounds outside.
"Impudent" also means "improperly forward or bold"--both definitions fit Winston's perspective on the forgeries, since he doesn't believe that records of the past should be altered. Winston's job requires him to act impudently towards truth. But according to the Party, the forgeries cannot be impudent because 1) they are part of proper procedures; 2) there are no forgeries.
Sometimes he talked to her of the Records Department and the impudent forgeries that he committed there.