an- 1
a prefix occurring before stems beginning with a vowel or h in loanwords from Greek, where it means "not," "without," "lacking" ( anarchy; anecdote ); used in the formation of compound words: anelectric. Also, before a consonant, a- .
[ 6 , IN- 3 , UN- 1 ]
an- 2
var. of ad- before n: announce.
an- 3
var. of ana- before a vowel: anion.