The headword (literally meaning 'in front of the hand', hence 'easily accessible') is either masculine/feminine accusative singular or neuter nominative/accusative singular of this two-termination adjective; apparently the latter, since the glossing is unambiguously neuter. (See further in any event n. 2 below.)
For more on this word see the next two entries, pi 2931 and pi 2932.
[1] No comparable glosses in other lexica (though the headword is paired with the first gloss in Philo Judaeus (of Alexandria), On the confusion of tongues 143.2, and with the second gloss in Galen 1.588.10 and 4.211.7 and Gregory of Nyssa, On Virginity 3.6.11).
[2] This phrase (which includes the headword), and indeed the whole entry, may be from disembodied Biblical commentary; cf. Maximus Confessor, Questions and Doubts 1.35, ?Origen, Commentary on Psalm 62:11, and Theodoret's commentary on the same passage: PG 80.1340.39; Gregory of Agrigentum, Commentary on Ecclesiastes 9.22.