A root whose most notable derivatives are Q. alqua, S. alph “swan”. The earliest iteration of this root was ᴱ√ḶKḶ from the Qenya Lexicon of the 1910s (QL/30); the other derivatives of this root from this period have to do with “appearance” such as ᴱQ. ilk- “to seem” (QL/42). By The Etymologies of the 1930s this root took on its later form, ᴹ√ALAK and had the gloss “rushing” with other derivatives like ᴹQ. alako “rush, rushing flight, wild wind”, N. alag “rushing, impetuous” and N. alagos “storm (of wind)” (Ety/ÁLAK). It was also an element in the name of S./N. Ancalagon “Biting Storm”. Given the continued appearance of this name of The Silmarillion (S/252), the 1930s meaning of this root may have survived, but it is hard to be certain since the name was only properly translated in the 1930s.
The 1930s root also had an unaugmented variant ᴹ√LAK with derivatives ᴹQ. (a)larka, N. lhagr “swift, rapid” (Ety/LAK²). Whether this unaugmented variant remained valid is unclear, but there is nothing in Tolkien’s later writing contradicting it either.
The root ᴹ√RAPH “snatch” itself first appeared in the Quenya Verbal System with a derived verb of ᴹQ. raf- of the same meaning (PE22/102), but it might have been a reemergence of the very first (deleted) gloss of the early root ᴱ√RAPA the Qenya Lexicon of the 1910s: “handle hastily, snatch, grab” (QL/79). As for √RAPH, it reappeared in green-ink revisions to the Outline of Phonology (OP2) from around 1970 with the gloss “seize, grab” and a derivative Q. arpo “seizer, thief” (PE19/89 and note #101). On the same page but from the originally layer of composition from the early 1950s there is the verb Q. raf- “wave, brandish” which may be related, though if so it must represent some semantic drift (PE19/89).