\In*du"si*um\, n.; pl. {Indusia} (-[.a]). [L., an under
garment, fr. induere to put on: cf. F. indusie the covering
of the seed spots of ferns.] (Bot.)
(a) A collection of hairs united so as to form a sort of cup,
    and inclosing the stigma of a flower.
(b) The immediate covering of the fruit dots or sori in many
    ferns, usually a very thin scale attached by the middle
    or side to a veinlet.
(c) A peculiar covering found in certain fungi.