Derived from dìdis (“big, large”) + -elis, with further etymology of the first component unclear. Possibly from Proto-Indo-European *deyh₂-dʰe-, from *deyh₂- (“to shine”), with semantic shift "shining" > "visible" > "large"; in this case, related to Homeric Greek δέατο (déato, “ showed themselves”), δῆλος (dêlos, “visible”), Vedic Sanskrit दीदाय (dīdā́ya, “ shines”), दीप् (dīp, “to blaze, glow”), and see the latter for more.
Windekens tentatively compares it with Ancient Greek Τῑτᾱ́ν (Tītā́n, “titan”) (possibly of Anatolian origin).
Cognate with Latvian dižs, dideļš.
dìdelis m (feminine dìdelė, neuter dìdeli) stress pattern 3b
| masculine | feminine | ||||
|---|---|---|---|---|---|
| singular | plural | singular | plural | ||
| nominative | dìdelis | didelì | dìdelė | dìdelės | |
| genitive | dìdelio | didelių̃ | didelė̃s | didelių̃ | |
| dative | dideliám | didelíems | dìdelei | didelė́ms | |
| accusative | dìdelį | dìdelius | dìdelę | dìdeles | |
| instrumental | dìdeliu | dideliãis | dìdele | didelėmìs | |
| locative | dideliamè | dideliuosè | didelėjè | didelėsè | |
| vocative | dìdelis | didelì | dìdele | dìdelės | |