ˈ ̷ ̷ ̷ ̷ˌklīn noun
( -s )
Etymology: therm- + -cline
1. : a temperature gradient ; especially : one marking sharp change
2. : a layer of water in a thermally stratified lake or other body of water separating an upper warmer lighter oxygen-rich zone from a lower colder heavier oxygen-poor zone ; specifically : a stratum in which temperature declines at least one degree centigrade with each meter increase in depth