Likewise in other lexica. The headword (which must be quoted from somewhere; there are numerous possibilities) is second-person singular imperative of the aorist e)/tlhn, from the root tla-/tlh-. Compare a scholion on Homer, Iliad 2.299 (where the plural imperative occurs: web address 1).
For other forms of this verb see epsilon 3324, tau 382, tau 703, tau 707, tau 710.