(verb)
to completely devote oneself to something, and to take great pleasure or delight in it;
e.g. They began to wallow in the tasks they had planned for themselves.
(verb)
to have an abundant or luxurious supply of something, or to show unrestrained indulgence in something;
e.g. She decided not to wallow in sadness any longer but to instead get up and do something useful.
(noun)
an instance of relaxed or ungainly rolling in mud or water, or of being completely absorbed/consumed by something;
e.g. After his wallow in self-pity, he decided to change his outlook on the incident.
(noun)
a sunken area filled with dust, mud, or shallow water, formed by large animals rolling or lying about, or such an area in which large animals roll/lie;
e.g. The elephants were playing in a wallow.