I discovered an interesting word in Irish yesterday – súilíní [ˈsˠuːl̪ʲiːn̪ʲiː] – which is a diminutive form of súil [sˠuːl̪ʲ] (eye) and means literally “small eyes”, and actually means eyelets, an aperture-sight, or bubbles. For example, uisce gan súilíní is still water (“water without bubbles”) [source].
More common Irish words for bubbles are bolgán and boilgeog.
The word súilíní is also used in Hiberno-English to mean “bubbles of fat floating on top of a stew or clear soup”, and is also written sooleens [source].
The word súil (eye) comes from *sūli, an alteration of the Proto-Celtic *sūle (suns), the dual of *sūlos, which is the genitive of *sāwol (sun), from the Proto-Indo-European *sóh₂wl̥ (sun). Apparently in Irish mythology the sun was seen as the “eye of the sky”, and the word for sun came to mean eye [source].
The words for sun in other European languages come from the same root, and most start with s, e.g. saũle (Latvian), sol (Swedish, Danish, Norwegian, Catalan, Spanish, Portuguese), Sonne (German), etc. There are some exceptions though, including haul (Welsh) heol (Breton), howl (Cornish) and ήλιος (ḗlios – Greek) [source].