| Language | Lexeme | Native script | Phonetic | Phonemic | Notes | |
|---|---|---|---|---|---|---|
| 135 | French | lac | lak | lak | ||
| 160 | Gaelic: Irish | loch | ˈl̪ˠʊx | ˈl̪ˠəxˠ | ||
| 127 | Italian | lago | ˈlaːɡo | ˈlaɡo | ||
| 129 | Ladin | lech | ˈlek | |||
| 143 | Portuguese | lago | ˈlaɡu | ˈlaɡu | ||
| 132 | Sardinian: Logudoro | lagu | laːɣu | laːɣu | ||
| 131 | Sardinian: Nuoro | lacu | ˈlakku | ˈlakku | ||
| 142 | Spanish | lago | ˈlaɣo | ˈlaɡo | ||
| 136 | Walloon | lac | lak | lak | ||
| 122 | Latin | lacus | ˈɫakus | ˈlakus | gen. lacūs | |
| 158 | Gaelic: Scottish | loch | l̪ˠɔx | |||
| 140 | Catalan | llac | ʎak | ʎak | ||
| 128 | Friulian | lât | ˈlaːt | ˈlaːt | ||
| 157 | Old Irish | loch | ˈl̪ˠaxˠ | ˈl̪ax | ||
| 147 | Gaulish | locu | Attested in place names, e.g. Penne-locos ("head of the lake"). | |||
| 123 | Romanian | lac | lak | lak | ||
| 126 | Neapolitan | laco | ˈlakə | ˈlakə | ||
| 133 | Old French | lac | ||||
| 134 | Anglo-Norman | lac | ||||
| 141 | Old Spanish | lago | ˈlaɡo | |||
| 159 | Gaelic: Manx | logh | lox | lox | loch | |
| 17 | Albanian: Standard | liqen | ||||
| 138 | Franco-Provençal | lé | ˈle | ˈle | ||
| 16 | Albanian: Gheg | liqen | ||||
| 137 | Old Occitan | lac | formerly: laus | |||
| 139 | Old Catalan | llac | ʎak | ʎak | ||
| 125 | Dalmatian: Vegliote | luọk | luok or luk | An alternative lag is a Venetian loanword, while Lac- appears as a frequent part of composed toponyms. | ||
| 144 | Portuguese: Brazilian | lago | ||||
| 130 | Milanese | lãch | laːk |
S.v. Proto-Celtic *loku- 'lake, pool' (cf. Lat. lacus, Gk. λάκκος, OE lagu, OCS loky).
S.v. *laku- 'Wasseransammlung in einer Grube, Lache, See'.
S.v. Lat. lacus, -ūs 'lake', from PIE *lok-u- 'lake' (cf. OIr. loch 'lake', OCS loky (gen.sg. lokъve) 'puddle, pool, reservoir', Gk. λάκκος 'pond').
