Kenōsis (κένωσις) is the substantive form of the Greek verb kenoō (κενόω), to empty, to pour out, to make void. Classical Greek used kenoō for emptying a vessel, draining a container, rendering something hollow. The theological term kenōsis derives from Paul's use of the aorist indicative ekenōsen (ἐκένωσεν) in Philippians 2:7: heauton ekenōsen morphēn doulou labōn (He emptied Himself, taking the form of a servant).

BDAG: to make empty, to deprive of content. Louw-Nida 87.70 places kenoō in the domain of status with the specific sense of laying down rank or standing. In Philippians 2 the verb does not mean Messiah ceased to be what He was; the surrounding hymn (2:6-11) makes plain that the emptying was a refusal to grasp at status (harpagmon, ἁρπαγμόν) rather than an ontological loss. The kenōsis is voluntary, relational, and oriented toward service.

The pattern matters for the husband-and-wife passage in Ephesians 5 because Paul writes the household code with Philippians 2 in his bones. The husband who loves his wife agapē-style on the model of Messiah's giving Himself up (paredōken heauton) is following the kenōsis pattern: he goes first into cost, lays down standing rather than asserting it, pours out before he receives. The Hebraic precursor lives in the Servant of Isaiah 53, who poured out his soul (he'erah lamavet nafsho, הֶעֱרָה לַמָּוֶת נַפְשׁוֹ, Isaiah 53:12). The Septuagint renders Isaiah 53:12 with paredothē (παρεδόθη, He was given up), the same root as paredōken in Ephesians 5:25.