leg, foot, be sufficient, counter for pairs of footwear
足 centers on the lower limb used for standing and walking: the leg or foot. The idea of sufficiency comes from having enough to stand on or fill a need, and the counter sense applies that to pairs of footwear.
足 is a pictograph of a leg and foot, with the modern form showing a rounded knee-like top 口 over the lower leg and foot shape 龰.
The top 口 looks like a knee joint, and the bottom 龰 is the lower leg and foot. Together they form a complete leg and foot.
For ソク, imagine a sock pulled over the foot: sock -> ソク, and the sock covers the foot shape of 足.
foot; paw; arm (of an octopus, squid, etc.)
satisfaction; contentment; gratification
to be sufficient; to be enough
insufficiency; deficiency; shortage; lack; scarcity; deficit
at one's feet; underfoot; one's step (as in "watch your step")
hands and feet; limbs
starting; inauguration; launch; founding; establishment; start-up
supplement; complement
ankle
footprints
unsatisfied; unsatisfactory; insufficient in some way; lacking something
right foot
both feet
left foot
to add (numbers)
scaffold; scaffolding
school trip; field trip; excursion; outing
barefoot
lack of sleep; insufficient sleep
a pair (of shoes or socks)
a step
(sound of) footsteps
to be sufficient; to be enough
preventing (someone) from leaving; confinement; keeping indoors; inducement to stay
gait; walk; stride; pace; step; manner of walking
sufficiency
legs and loins; lower body
stepping (in place); stamping (up and down); stomping; marking time (for a soldier)
tabi; traditional split-toe socks
addition
running fast; double time
foothold; footing; toehold; stepping stone
customer traffic; customers; custom
pace; step
shod feet; wearing shoes
to add (to); to add on; to append
running away; escaping on foot
swiftness of foot; fast runner
fast (walking); quick; brisk
turnout (of people)
overeagerness; rashness
feeling of satisfaction
lack of physical exercise; insufficient exercise; inactivity
customer satisfaction