side, lean, oppose, regret
側 centers on the idea of being beside something: a physical side, leaning toward a direction, or taking a stance. The meanings 'oppose' and 'regret' are less common and may stem from taking a side against something or feeling regret from a particular standpoint.
側 combines 亻 (person) with 則, which likely contributes the sound and the idea of a rule or standard. The compound suggests a person positioned beside something, perhaps as a standard or measure.
A person 亻 standing next to a rule 則: imagine someone leaning against a measuring stick, marking the side of something.
For ソク, picture a sock leaning against the side of a drawer: sock -> ソク, and the sock is beside the drawer's edge.
(place) near by; (place) close by; (place) right next to; the side (of something); beside; vicinity; proximity; neighbourhood (neighborhood)
side (of something, or taking someone's side); part
side; flank; profile; sidelight; lateral
inside; interior; inner part
exterior; outside; outer; external; lateral
right side; right-hand side
left side; left-hand side
the reverse (side); back (side); other side; hidden side; behind the scenes
west side; west bank
north side; north bank
south side
east side; east bank
both sides
close aide (of a powerful person); close associate; entourage; attendant; retainer
one side
engawa; external corridor on the outer side of traditional Japanese houses
opposite side; other side; other party
gutter; ditch
upper side; surface
the front