- paraphrase with 'enter' (mitta-)
- figure out the transitive verb (yan-? yat-? yatya-? yatta-? yanta-?) and then make it reflexive (as in Russian sya) yantaxe?
- paraphrase with 'become a member'

Elaran already suggested yanya- in Discord, and I agreed.

ah, well, sorry then

+Tamas Ferencz why sorry? Your ideas are very good, too. I think I will use yanta- for plain transitive "to join". I very much appreciate your concern and contribution! You have a much longer experience of studying Quenya!

There are other possibilities/synonyms for the transitive join : e.g. *erta- "unite"; *limya- "link" from LIM (cf. málime).

+Tamas Ferencz indeed all these words are good in their own way!

nut- 'tie, bind'; *himta- '(make) stick, glue'