fos·so·ri·al
Pronunciation: fä-'sOr-E-&l, -'sor-
Function: adjective
Etymology: Medieval Latin fossorius used for digging, from Latin fossor digger, from fodere
1: adapted to digging

noc·tur·nal
Pronunciation: näk-'t&r-n&l
Function: adjective
Etymology: Middle English, from Middle French or Late Latin; Middle French, from Late Latin nocturnalis, from Latin nocturnus of night, nocturnal, from noct-, nox night
1 : of, relating to, or occurring in the night

2 : active at night

cre·pus·cu·lar
Pronunciation: kri-'p&s-ky&-l&r
Function: adjective
1 : of, relating to, or resembling twilight : DIM
2 : active in the twilight