Salmoneus wrote: ↑19 Feb 2019 18:39
So your TRAP ones are all TRAP in RP, except 'castle', and 'rather', which is, as I say, clearly an independent analogy. Oh, and "castor" (except for "Castor", which being a loanword takes TRAP. Wait, does that mean (given American BATH loanwords) that some US dialects say "castor" for Castor and "Castor" for castor?). Castigate I've heard either way, but I'd always have TRAP. I think your "castor" must just be an irregularity, given both the phonological context and the opposite vowel in 'caster', which should probably already have been homophonous by then.
"Castor" as in Castor and Pollux? The Latin lexical stratum takes TRAP in America, not PALM. But I don't know if the dialect of the dictionary would've been any different - Castor isn't in it.
(And loanwords in the dictionary that don't take TRAP take PALM, not BATH: guava, guano, lakh...)
On cast, caster, and fasten, there's agreement. "Asp" is the only -sp# word with TRAP in SSBE (though a couple are variable), so analogy is not surprising. -s# seems to be where the SSBE shift was most incomplete, because it's a total mess, which the US seems to have completed. [eg traditionally BATH Mass, but TRAP mass, though the former has analogised to the latter for most speakers now.]
TRAP: answer, basket, bass, cassava (with initial stress!), castrel (i.e. kestrel), dastard, fastidious, gas, gastric, gather, grand, hasp, hassock, hast, lasso, lather, mantel, mantis, pantaloon, all panth- words, pantry, passenger, passible, pastern, phantom, plant, plantain, plasm, plastic, ranch, rant, rascal, scant, shanty, tantalize, tantamount, tantrum, tassel, all trans- words
BATH: advance, advantage, ant, ask, ass, chance, chant, fast, flask, gasp, ghastly, glance, glass, graft, grant, grass, haft, lass, lath, mandarin (/ˌmandaˈri:n/?!), masque, Mass, mass, nasty, pant, pass, passage, Passover, passport, past, pastime, pastor, pasture, plaster, prance, raft, rafter, rasp, shan't, slant, staff, stanch, task, trance, vast
PALM: calf, calve, half, laugh, salve,
PALM: haunch, haunt, gaunt, gauntlet, jaunt, jaunty, launch, launder, taunt, vaunt (given as PALM or THOUGHT)
(In AmEng now, the first set takes TRAP and the second takes THOUGHT. "Aunt", of course, varies.)
/z/ in "basilisk" - presumably /s/ is a spelling pronunciation
THOUGHT in "falcon" - the spelling pronunciation hadn't caught on yet in the 1890s
either THOUGHT or GOAT in "groat" and "groats" (now always GOAT)
LOT in "halibut" and "scallop" (now TRAP, I think - spelling pronunciation, but wouldn't we expect THOUGHT? and TRAP in "shallop")
also LOT in "wallet", "wallop", "wallow", "walnut"
TRAP in "palmetto"
w + NORTH (i.e. THOUGHT + -r): all quart- words, vs. default LOT for qua- (quart- varies in AmEng)
START (i.e. PALM + -r): sarsparilla (always /sæs-/ now)
I've been pronouncing "talon" wrong all my life, apparently it has initial stress
Unstressed 'short' <a> is given as BATH, so you get alternations like /ˈgrætɪtu:d/ vs. /graˈtu:ɪtʌs/.