Most likely derived from mukula (“round thing, lump; kid, child”), the variant muksu seems to originate from Satakunta, northern Tavastia or southern Ostrobothnia. It entered the standard language in the early 20th century.
More words beginning with mu- with the meaning "child" are attested from dialects, including mukulainen, mukura, mulikka and muskula.
muksu
| Inflection of muksu (Kotus type 1/valo, no gradation) | ||||
|---|---|---|---|---|
| nominative | muksu | muksut | ||
| genitive | muksun | muksujen | ||
| partitive | muksua | muksuja | ||
| illative | muksuun | muksuihin | ||
| singular | plural | |||
| nominative | muksu | muksut | ||
| accusative | nom. | muksu | muksut | |
| gen. | muksun | |||
| genitive | muksun | muksujen | ||
| partitive | muksua | muksuja | ||
| inessive | muksussa | muksuissa | ||
| elative | muksusta | muksuista | ||
| illative | muksuun | muksuihin | ||
| adessive | muksulla | muksuilla | ||
| ablative | muksulta | muksuilta | ||
| allative | muksulle | muksuille | ||
| essive | muksuna | muksuina | ||
| translative | muksuksi | muksuiksi | ||
| abessive | muksutta | muksuitta | ||
| instructive | — | muksuin | ||
| comitative | See the possessive forms below. | |||