swem-
“to swim, to be in motion”swim, move through water
Root for swimming, yielding Old English swimman, German schwimmen.
Discussion
The PIE root *swem- (to swim, to be in motion through liquid) is primarily preserved in the Germanic branch, where it generated the common word for human locomotion through water — one of the basic physical activities for which PIE speakers had a dedicated verb.
Old English swimman (to swim, to float, to move through water) continues PGmc *swimmaną directly, and the modern English swim is one of the most phonologically conservative words in the language — barely changed in over a thousand years of attested history. German schwimmen, Dutch zwemmen, and Old Norse svimma/symja preserve the cognate set across Germanic. The variation between *sw- and *s- in the initial cluster reflects dialectal differences within Proto-Germanic.
The semantic extension to dizziness is preserved in English swim ("my head swims") and more transparently in German Schwindel (dizziness, swindle — the latter from the sensation of the world spinning). The connection between swimming and vertigo reflects the physical experience: the disorientation of being suspended in water, lacking firm ground, mirrors the sensation of dizziness. Old English swimol (dizzy) makes the link explicit.
Outside Germanic, the root is less securely attested. Some scholars connect Latin nāre (to swim, to float) to a related formation, but the phonological derivation requires intermediate steps that are not universally accepted. The Sanskrit cognate, if one exists, has not been securely identified.
This limited distribution — robust in Germanic, uncertain elsewhere — is not unusual for activity verbs in PIE. Many physical actions were lexicalised differently in different branches: the PIE speakers presumably swam, but the specific root they used for the activity may have been replaced in most daughter languages while surviving only in Germanic. Alternatively, *swem- may have been a Proto-Germanic innovation rather than a direct PIE inheritance, with the PIE status of the root remaining genuinely uncertain.
The word's resistance to borrowing is characteristic of basic bodily activity terms. English never adopted a Latin or French word for swimming despite the wholesale importation of Romance vocabulary after 1066 — a pattern typical of fundamental physical verbs (eat, drink, sleep, walk, run, swim) that remain stubbornly Germanic in English while their more abstract counterparts were replaced by French-Latin equivalents.
Notes
Pokorny 1046. Primarily Germanic attestation.
Related Roots
English Words from *swem-
These modern English words descend from this root. Each page traces the full journey from PIE to present-day English.