ケイ, キョウ, うやま.う, け, たか, たかし, たけ, とし, のり, ひろ, ゆき, よし
awe, respect, honor, revere
JLPT2 G6 S12 F1078
The relevant seal inscription form of the left-hand element# is 人 person + an element combining horns and a mouth → person who cries out and goes stiff with fear upon being charged by a ram. 敬 adds 攵 action indicator → *be stiff/formal/ceremonious* (compare 改 and 僵) → *respect*. Note that the left-hand element of 敬 is etymologically distinct from the independent character 苟.
[Full Kanji Etymology List]