I

Primary Meanings of I

1.
n
the 9th letter of the Roman alphabet
2.
n
the smallest whole number or a numeral representing this number
3.
n
a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)
Full Definitions of I
1

n the 9th letter of the Roman alphabet

Synonyms:
i
Type of:
alphabetic character, letter, letter of the alphabet
the conventional characters of the alphabet used to represent speech
2

n the smallest whole number or a numeral representing this number

Synonyms:
1, ace, one, single, unity
Types:
monad, monas
a singular metaphysical entity from which material properties are said to derive
singleton
a single object (as distinguished from a pair)
fellow, mate
one of a pair
Type of:
digit, figure
one of the elements that collectively form a system of numeration
3

n a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)

Synonyms:
atomic number 53, iodin, iodine
Types:
iodine-131
heavy radioactive isotope of iodine with a half-life of 8 days; used in a sodium salt to diagnose thyroid disease and to treat goiter
iodine-125
light radioactive isotope of iodine with a half-life of 60 days; used as a tracer in thyroid studies and as a treatment for hyperthyroidism
Type of:
chemical element, element
any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
halogen
any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions

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