When you hear the word solicitous, think of your mom — attentive, caring, and concerned. It's nice when your waiter gives you good service, but if he or she is solicitous, the hovering might annoy you.
Solicitous comes from the Latin roots sollus "entire" and citus "set in motion." If someone is solicitous, they are entirely set in motion caring for you. Your neighbors are solicitous if they try to help your family out all the time. Use this word too if you're eager to do something. A good student will be solicitous to appear interested in what the teacher says — even when it's not that interesting.