Grammatical term for λυετέον

Greek Learning Greek
1

Λυετέον and λυετόν are verbal adjectives expressing necessity and possibility, respectively. Are there any (old) grammatical terms for each of them severally? The latter might perhaps be called a potential verbal adjective; but what about the former? Gerundive, perhaps? (Or is that used of both?)

2

For -τέον, Smyth refers us in parenthesis to the Latin gerundive (see here), but he seems to avoid adopting the term itself. For the -τός he doesn’t even bother (here). Maybe in older comparative grammars you’ll find something?

3

Chantraine speaks of adjectifs verbaux (Morphologie historique du grec p. 283—285), and Bornemann—Risch speak of Verbaladjektive (p. 97, 256—257), as does Schwyzer (p. 501—502, 810—811), in their respective Griechische Grammatiken. Schwyzer mentions in addition the verbal adjective endings -ιος -νός -άς.

4

I’m not aware of any special terms that distinguish verbal adjectives in -τέος from those in -τός. Transferring Latin grammatical terms to Greek linguistic phenomena doesn’t necessarily work well.

For the verb λυω, the verbal adjectives are λυτέος and λυτός. LSJ:

λυτ-ός , ή, όν,
A.that may be untied, Pl.Ti.41b, al.
II. that may be dissolved, soluble, ὑφ᾽ ὕδατος ib.60d, cf. Arist. Mete.383b13. Adv. -τῶς solubly, Id.PA649a32.
III. of arguments and problems, refutable, soluble, Id.Rh.1357b13.

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dluto%2Fs

λυτέος 1 verb. adj. of λύω,

one must solve, Plat.
1 λυ^τέος, ον

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0058%3Aentry%3Dlute%2Fos

The verbal adjectives are typically formed from the stem of the aorist passive. See Smyth 471:

  1. Verbal Adjectives.—Most of the verbals in -τός and -τέος are formed by adding these suffixes to the verbal stem of the aorist passive (first or second). Thus, φιλητός, -τέος (ἐ-φιλή-θην); πειστός, -τέος (ἐ-πείσ-θην); τελεστός, -τέος (ἐ-τελέσ-θην); σταλτός, -τέος (ἐ-στάλ-ην); βλητός, -τέος (ἐ-βλή-θην). On the accent of compound verbals, see 425 c.

http://www.perseus.tufts.edu/hopper/text?doc=Smyth+grammar+471&fromdoc=Perseus%3Atext%3A1999.04.0007