Literally: warm – thick – serious / kind – truth / reality
Alternately: Calm, kind, and sincere. Gentle and serious. A good and honest person.
Notes: This compound may have come from the I Ching, and be associated with the 26th hexagram… although this connection is only asserted by one of my sources and may be apocryphal; another source attests its use, in Japanese at least, only since 1843.