- Main Entry:
-
rar·e·fy
- Variant(s):
- also rar·i·fy \ˈrar-ə-ˌfī, ˈrer-\

- Function:
- verb
- Inflected Form(s):
- rar·e·fied also i·fied; rar·e·fy·ing also i·fy·ing
transitive verb
: to make rare, thin, porous, or less dense : to expand without the addition of matter
intransitive verb
: to become less dense