Where does “tantost” come from?

tantost (Old French) comes from Old French tant, from Latin tantus, from Latin tam, from Proto-Indo-European téh₂m, from Proto-Indo-European séh₂, from Proto-Indo-European só — this; that.

tantost (Old French): as soon as

Definitions

as soon as

Ancestry of “tantost”, step by step

tantost traces back through two separate lines of ancestry.

via Old French tant

Step	Language	Word	Meaning
1	Old French	tant	so much, so many; so much; such
2	Latin	tantus	of such size, of such measure; so much, so great
3	Latin	tam	so, so much, to such an extent, to such a degree
4	Proto-Indo-European	téh₂m	—
5	Proto-Indo-European	séh₂	—
6	Proto-Indo-European	só	this; that

via Old French tost

Step	Language	Word	Meaning
1	Old French	tost	early; soon; quickly; straight away
2	Latin	tostum	nominative neuter singular of tostus; accusative...
3	Latin	tostus	roasted, toasted, scorched, having been roasted;...
4	Proto-Italic	*torstos	—

Every word from Proto-Indo-European só →Every word from Proto-Indo-European séh₂ →Every word from Proto-Indo-European téh₂m →