wart
疣 centers on a small, abnormal skin growth: a wart. It is a specific medical term with no broader conceptual cluster.
疣 combines the sickness radical 疒 with the phonetic component 尤, which likely contributed the sound. The character specifically denotes a wart as a skin ailment.
The sickness enclosure 疒 wraps around 尤, like a stubborn wart growing on the skin. Picture a wart as a small, abnormal bump that the body wants to heal.
For ユ, imagine a wart that looks like the letter 'U' on your skin: U -> ユ, and you want to remove it.
wart
warts; wart-like bumps
Anderson's crocodile newt (Echinotriton andersoni); Anderson's newt; Ryukyu spiny newt; Japanese warty newt
wax-leaf privet (Ligustrum japonicum); Japanese privet
gibbous duckweed (Lemna gibba); swollen duckweed; fat duckweed
Batillaria zonalis (small sandy shore snail)
warthog (Phacochoerus aethiopicus)
toad with wart-covered skin (esp. the Japanese toad or the wrinkled frog)
Thais clavigera (species of rock shell)
wart; verruca
parapodium
thornback ray (Raja clavata); thornback skate
Japanese butterfish (Psenopsis anomala); melon seed
snub-nosed monkey (Rhinopithecus spp., esp. the golden snub-nosed monkey, Rhinopithecus roxellana)
spinneret (of a spider)
plantar wart