ὑποστορεννύναι -> spread under

[spiros]

ὑποστορεννύναι

Woodhouse again.

[billberg23]

Theoretical active infinitive, hapax ὑποστορέννυσθαι in Theophrastus, Charakteres 22.5.2.  LSJ doesn't list the compound separately, but gives στορέννυμι ("spread," "stretch") as an alternative to στόρνυμι, and enters ὑποστόρνυμι ("spread under") without mentioning Theophrastus' (or anyone's) use of the alternative ὑποστορέννυμι.

[spiros]

So ὑποστορέννυναι/στορνύναι/στορεννύναι are valid infitives?

https://lsj.gr/wiki/spread

[billberg23]

Not the first, which would be paroxytone (I was wrong about the accent) if attested in ancient Greek (which it isn't).  The third is theoretically correct (not attested in ancient Greek).  The second is attested only in Aeschylus, Agamemnon 909.