Lexicon :: Strong's G3311 - merismos

μερισμός, μερισμοῦ, ὁ (μερίζω), a division, partition (Plato, Polybius, Strabo, (others));
1. a distribution; plural distributions of various kinds: πνεύματος ἁγίου, genitive of the object, Hebrews 2:4.
2. a separation: ἄχρι μερισμοῦ ψυχῆς καί πνεύματος, which many take actively: 'up to the dividing' i. e. so far as to cleave asunder or separate; but it is not easy to understand what the dividing of the 'soul' is. Hence, it is more correct, I think, and more in accordance with the context, to take the word passively (just as other verbal substantive ending in μος are used, e. g. ἁγιασμός, πειρασμός), and translate even to the division, etc., i. e. to that most hidden spot, the dividing line between soul and spirit, where the one passes into the other, Hebrews 4:12; (cf. Siegfried, Philo von Alex. as above with, p. 325f).

BLB Scripture Index of Thayer's