Basic potions (not decoctions) and bomb names follow the same pattern. The different levels of the items are named using numbers, so for example Thunderbolt is Thunderbolt 1,
Enhanced Thunderbolt is Thunderbolt 2 etc.

For the most part the in game names match up to the code names for the items, but there are some exceptions which are listed below.

[In game names] [Code names]
Devil's Puffball Devils Puffball
Dimeritium bomb Dwimeritium Bomb
Dragon's Dream Dragons Dream
Moon Dust Silver Dust Bomb
Northern Wind White Frost

Petri's Philtre Petri Philtre
White Raffard's Decoction White Raffards Decoction

Alghoul Decoction Mutagen 15
Ancient Leshen Decoction Mutagen 22
Arachas Decoction Mutagen 2
Archgriffin Decoction Mutagen 4
Basilisk Decoction Mutagen 23
Chort Decoction Mutagen 8
Cockatrice Decoction Mutagen 3
Doppler Decoction Mutagen 11
Earth Elemental Decoction Mutagen 20
Ekhidna Decoction Mutagen 21
Ekimmara Decoction Mutagen 7
Fiend Decoction Mutagen 16
Foglet Decoction Mutagen 9
Forktail Decoction Mutagen 17
Grave Hag Decoction Mutagen 18
Griffin Decoction Mutagen 27
Katakan Decoction Mutagen 1
Leshen Decoction Mutagen 26
Nekker Warrior Decoction Mutagen 25
Nightwraith Decoction Mutagen 6
Noonwraith Decoction Mutagen 13
Reliever's Decoction Mutagen 28
Succubus Decoction Mutagen 14
Troll Decoction Mutagen 12
Water hag Decoction Mutagen 5
Werewolf Decoction Mutagen 24
Wraith Decoction Mutagen 19
Wyvern Decoction Mutagen 10

Foglet Fogling
Fire elemental elemental_ifryt
Ice Elemental elemental_ice
Endrega (various types) Endriaga