Intensifying prefix for superlatives: very; of them all
köken: From aller, the genitive form of alle (“all”), from Middle High German al, from Old High German al, from Proto-Germanic *allaz. Compare English all-, English alder-.
aller- + erste (“first”) → allererste (“very first”)
aller- + größte Stadt (“the biggest city”) → allergrößte Stadt (“the very biggest city / the biggest city of them all”)
aller- + meist (“most”) → allermeist (“almost all”)
eş: brâment, énormément, en sale, moult, beaufaire, bellement
köken: Inherited from Old French biau cop, first attested circa 1210. Equivalent to beau (“nice, beautiful”) + coup (“hit, strike”). The latter word also means “helping of soup or beverage”, first attested circa 1375, whose sense may have triggered or reinforced beaucoup to mean “a lot”.
aile: à beaucoup près, c'est beaucoup, de beaucoup, il s'en faut de beaucoup, pour beaucoup
köken: Inherited from Old Anatolian Turkish چُوقْ (çoq), چوخ (çoḫ), from Proto-Turkic *čok (“many, very; to gather, multiply”). Cognate with Turkish çok, Gagauz çok, Crimean Tatar çoq, etc.
very, extremely · in particular, particularly · synonym of eritellen (“specifying, allocating”)
eş: epätavallisen, erinomaisen, hirveän, huikean, hyvin, huomattavan
köken: eri + -ttäin (distributive plural). Equivalently, from the second infinitive instructive of erittää (“to specify”) (standard erittäen), and erittäin is very likely one of the prototypes for the -ttain suffix in general. Semantic evolution seems to run from senses 3-to-2-to-1.
köken: From the Latin adjective fortis, fortem, from Old Latin forctis, fortis, from Proto-Indo-European *bʰerǵʰ- (“to rise, high, hill”). Compare the same semantic development in French fort, Occitan fòrça, Ligurian foart (attested in Menton, France). In older Romanian, the word was also used as a freestanding adverbial, in addition to simply as an intensifier.