This compound verb means to fill up in turn or supply what is lacking. Paul uses it in Colossians 1:24 in a famously difficult statement: 'I fill up in my flesh what is still lacking in regard to Christ's afflictions.' The verb combines 'in turn/instead' (ἀντι-) with 'fill up' (ἀναπληρόω), suggesting reciprocal or compensatory filling. Classical usage included filling vacancies and balancing accounts. Spanish 'completo' (complete), French preservation of the Greek, and German 'ergänzen' (supplement) all suggest completing or supplementing.