εἴην
From LSJ
ἑτέρως ἠδύνατο βέλτιον ἢ ὡς νῦν ἔχει κατεσκευάσθαι → otherwise they could have been constructed better than they are now (Galen, On the use of parts of the body 4.143.1 Kühn)
English (LSJ)
French (Bailly abrégé)
opt. de εἰμί.
Russian (Dvoretsky)
εἴην: opt. к εἰμί.
Greek (Liddell-Scott)
εἴην: εὐκτ. ἀορ. β΄ τοῦ ἵημι· ἀλλ’ εἴην εὐκτ. ἐνεστ. τοῦ εἰμὶ (ὑπάρχω).
English (Strong)
optative (i.e. English subjunctive) present of εἰμί (including the other person); might (could, would, or should) be: mean, + perish, should be, was, were.