Verb (1-dan, intransitive)
1.  to fall down;  to drop;  to fall (e.g. rain);  to sink (e.g. sun or moon);  to fall onto (e.g. light or one's gaze);  to be used in a certain place (e.g. money)
occ. 堕ちる for depravity and 墜ちる for a crash
2.  to be omitted;  to be missing
3.  to decrease;  to sink
4.  to fail (e.g. exam or class);  to lose (contest, election, etc.)
5.  to crash;  to degenerate;  to degrade;  to fall behind
6.  to become indecent (of a conversation)
7.  to be ruined;  to go under
8.  to fade;  to come out (e.g. a stain);  to come off (e.g. makeup);  to be removed (e.g. illness, possessing spirit, name on a list)
9.  to fall (into someone's hands);  to become someone's possession
10.  to fall (into a trap);  to fall (for a trick)
11.  to give in;  to give up;  to confess;  to flee
12.  to fall;  to be defeated;  to surrender
13.  to come to (in the end);  to end in
14.  to fall (in love, asleep, etc.)
15.  to swoon (judo)
16.  to consent;  to understand
17.  to go down (of a website, server, etc.);  to crash
18.  to log out (of an online game, chat room, etc.);  to drop out;  to leave;  to go offline
20.  to move to the depths
of fish when it gets cold