Verb (5-dan, く, intransitive)
1.  to calm down;  to compose oneself;  to regain presence of mind
2.  to calm down;  to settle down;  to die down;  to become stable;  to abate
3.  to settle down (in a location, job, etc.);  to settle in
4.  to be settled;  to be fixed;  to have been reached
of an arrangement, conclusion, etc.
5.  to harmonize with;  to harmonise with;  to match;  to suit;  to fit
6.  to be unobtrusive;  to be quiet;  to be subdued
usu. used pronominally as 落ち着いた