概

gài
Left: tree 木, right: previous/before 既 (It is 'not good' 艮 with a 'false tusk' 牙, that's already since, ..)
A tree and a not-good tusk (as drawn) are approximately in general (the same)?

既

jì
Left: not good 艮 (良 would be good, but as one stroke is missing it is 'not good' 艮), right: (false tusk 牙)
It is not good with a false tusk, that's already since, ..

慨

kǎi
Left: feeling 忄, right: already, since 既 (It is 'not good' 艮 with a 'false tusk' 牙, that's already since, ..)
With feelings she is already rather generous.

溉

gài
Left: water 氵, right: already, since 既 (It is not good 艮 with a false tusk 牙, that already since, ..)
Water is not good (suitable) to be used in a false tusk for: irrigation.

暨

jì
Top: already, since 既 (It is 'not good' 艮 with a 'false tusk' 牙, that's already since, ..), bottom: sun rise 旦 (The sun 日 above the horizon 一)
Already since the sun is above the horizon, until it reaches to a limit.