on foot, junior, emptiness, vanity, futility, uselessness, ephemeral thing, gang, set, party, people
徒 centers on the idea of going on foot, which extends to people who follow or walk together (a gang, set, or party) and to things that are empty, vain, or futile—like walking without purpose. The junior sense fits as a follower on foot.
徒 combines 彳 (movement) and 走 (run), suggesting going on foot. The extended meanings of futility and emptiness likely developed from the idea of walking without purpose or substance.
The left side 彳 suggests a path or movement, and the right side 走 means run. Picture a group of people moving on foot along a path—a gang or party walking together, which can feel aimless and futile.
For ト, imagine a toe walking on foot: toe -> ト, and the kanji is all about going on foot.
pupil; student; schoolchild
walking; going on foot
believer; adherent
ordinary person; untitled individual
apostle; disciple
Christian
rioters; mob; insurgents
layman; believer; adherent; follower; laity
vain; futile; transient; frivolous
pagan; heretic; heathen
student; follower; students and pupils
Buddhist
foot soldier (Edo period); samurai on foot
tedium; boredom; ennui
saint
conspirators; faction; cabal; clique
fruitless effort; wasted effort; abortive scheme; futility
Essays in Idleness by Yoshida Kenkou (1283-1352)
uselessly; pointlessly; in vain; to no purpose; for nothing; idly
apprentice