ŝtrumpo

The base arrives after the derivative. A ŝtrumpeto is a sock, and it is ŝtrumpo plus the diminutive -et-: a little stocking. The sock page went up at rank 2272, in chapter 24, and had to explain a word it could not link to, because ŝtrumpo itself sits here at 2422. Now both exist and the pair closes.

That ordering is not an accident of our corpus, it is a fact about clothing. Most people put socks on every morning and stockings on a handful of times a year, so the derived word is genuinely commoner than the word it derives from. Esperanto does not mind. The affix system does not require you to meet the parent first; it only requires that when you do meet it, the child suddenly makes sense in retrospect.

What it covers. Ŝtrumpo is the long one, up the leg: a stocking, and by extension the long football sock. Ŝtrumpeto stops at the ankle. Ŝtrumpkalsono welds the stocking to kalsono, the underpants, and gives you a pair of tights, which is one of those compounds that is either transparent or absurd depending on how long you look at it. Ŝtrumpligilo is a garter.

Note the initial ŝt-. Esperanto allows consonant clusters that English spells but softens, and this one is pronounced in full: ŝ then t, no vowel smuggled in between.