SOON, SOONER, SOONEST
ADJECTIVES
..888 — RATHEST soonest, quickest, most preferable; most eager obs.
1225 — TITE quickly, soon → obs. exc. Eng. dial.
1425 — RATHEREST soonest → obs.
1900 — EFTEST soonest, quickest, most convenient → Eng. dial. (Bk.)
1908 — SOON AS DAMMIT exceedingly quick, or almost immediate, soon → UK
ADVERBS
..825 — RATHE denoting rapidity in the performance or completion of an action; quickly, rapidly, swiftly, esp. without delay, promptly, soon → obs.
..888 — RADLY quickly, promptly, without delay, soon → obs.
..888 — RATHEST soonest, most readily → obs.
1225 — TIT quickly, soon → obs. exc. Eng. dial.
1225 — TITELY — TITLY quickly, speedily, smartly; soon → obs. exc. Eng. dial.
1250 — RAD quickly, readily, soon → obs.
1250 — UNGHERE soon, quickly → obs.
1300 — TITTER sooner, more readily, more willingly, rather → obs. exc. N. Eng. dial.
1320 — YERNE quickly, without delay, immediately, directly, soon → obs.
1450 — SANDER — SONDER sooner → obs.
1400 — BETIMES in a short time, soon, speedily, anon, forthwith
1450 — HASTY hastily; quickly, rapidly, soon
1475 — ANON in a little while; soon, shortly
1500 — SUDDENLY at an early date, early; soon, speedily; shortly (after) → obs.
1549 — HASTILY soon, without delay, shortly, suddenly → obs.
1616 — BELIVE soon, by-and-by → obs. exc. Sc.
1722 — BIMEBY presently, soon, before long → Amer. dial.
1790 — BAMBY presently, soon; by-and-by → Eng. dial.
1790 — ENOW shortly, very soon, in a moment, presently, by and by → Sc. & Eng. dial.
1847 — ESTITE as soon, rather → Sc. & N. Eng. dial.
1876 — VENNY sooner, rather → Eng. dial. obs.
1902 — IN A TWITTER soon, quickly → Eng. dial. (Bk.)
1911 — BELIE speedily; soon → Sc. (Bk.)
1942 — BEANTOTE soon (French bientôt) → Amer. sl. (Bk.)
PHRASES
1955 — ASAP as soon as possible → US, orig. military usage
Lexicophilia 