From WordNet (r) 3.0 (2006) [wn]:
rarely
adv 1: not often; "we rarely met" [syn: rarely, seldom]
[ant: frequently, oft, often, oftentimes,
ofttimes]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Rarely \Rare"ly\ (r[^a]r"l[y^]), adv.
1. In a rare manner or degree; seldom; not often; as, things
rarely seen.
[1913 Webster]
2. Finely; excellently; with rare skill. See 3d Rare, 2.
[1913 Webster]
The person who played so rarely on the flageolet.
--Sir W.
Scott.
[1913 Webster]
The rest of the apartments are rarely gilded.
--Evelyn.
[1913 Webster]