Do you like Gus as a short name, but are not so keen on Augustus and its related names August and Augustine?
Here are some alternatives!
Agastya — A name from Hindu mythology. Agastya is a name of Shiva, as well as the name of a legendary Hindu sage, believed to have received many of the earliest mantras which feature in the Rig Veda from Brahman. It is also the Indian name for Canopus. It comes from the Sanskrit aga mountain + asyati ‘to throw’, and is usually translated as ‘mountain-thrower’.
Angus — a classic and very old Gaelic name, from the Old Irish óen ‘one’ + gus ‘excellence’, ‘force’ and ‘courage’. The standard modern Gaelic form is Aonghas, but Aengus, Aonghus, Oenghus and Óengus are all known. In Irish myth Aengus is the God of love, youth and poetic inspiration.
Asparagus – the vegetable. The name is ancient, coming from the Greek asparagos, of uncertain origin, though possibly from the Proto-Indo-European *sp(h)er(e)g- ‘to spring up’. In the past, also much valued for its healing and healthful properties, hence its botanical name Asparagus officinalis.
Constantine — Gus is often found as a short-form for Constantine among the Greek community. The name of the Roman Emperor responsible for legalizing Christianity in the Roman Empire, Constantine is revered as a saint in the Orthodox church. His name derives ultimately from the Latin constans ‘firm’, ‘stable’ and ‘invariable’.
Crataegus — the botanical name for hawthorn. One very much for Pagans and Nature lovers! Comes ultimately from the Greek krataigos ‘thorn-tree’.
Džiugas — a traditional Lithuanian name, from the Lithuanian džiugus ‘cheerful’.
Fergus – Another old Gaelic name (properly Fearghus or Fearghas) from the Old Irish fer ‘man’ + gus ‘excellence’, ‘force’ and ‘courage’.
Finegas — a name from Irish mythology. Finegas was an elderly druid who taught Finn McCool. From the Old Irish fionn + éices ‘scholar’, ‘sage’, ‘seer’ and ‘poet’.
Gaspard – French form of Jasper, which most likely comes from the Persian: khazāndār ‘treasurer’. There’s also the Spanish Gaspar and Italian Gaspare.
Gaston — French name meaning ‘a Gascon’, i.e. ‘from Gascony’.
Ghassan — Arabic name meaning ‘youth’.
Gurgustius — the name of a legendary king of Britain. From Welsh gor- ‘super’ + gwst ‘power’, ‘force’ and ‘excellence’.
Gus — nothing stopping you just using Gus on its own! Many have. Remember that in Old Irish, gus means ‘excellence’, ‘force’ and ‘courage’. There’s also the pet-form Gussie.
Gust – short form of Gustavus and Augustus. Gust was in the US top 1000 as a name in its own right in 1880.
Gustavus — Latinized form of German Gustav, a very old name of uncertain origins. Often translated as meaning ‘staff of the Goths’, its oldest form Chustaffus suggests that its first element might be the Old German chud, from chûton ‘to meditate’ –giving Gustav the meaning ‘staff of meditation’. The French form is Gustave, Italian Gustavo, and Gustaf is Scandinavian.
Icotasgus — an attested Brythonic name, the first element isn’t certain (it may be *iko- ‘woodpecker’). The second is *tasgo- ‘badger’.
Magus — Latin magus ‘mage’, ‘learned man’.
Moritasgus — a Celtic God, identified by the Romans with Apollo, whose name means ‘great badger’.
Pagasaeus — an epithet of Apollo. It comes from the Greek harbor Pagae, itself meaning ‘(fishermen’s) nets’ in ancient Greek.
Radagast — a wizard in Tolkien’s Lord of the Rings. It means ‘tender of beasts’ in Adûnic.
Vegas — adoption of the name of the US city of Las Vegas. This is from the Spanish vega meaning ‘fertile plain/valley’ and ‘meadow’.
Zygus — the ancient Greek name for Libra, from zugos ‘yoke (of a plough)’, ‘crossbar’ and ‘balance beam’.