An adverb rooted in the noun for 'gift' (dorea), carrying the core idea of something given without expectation of return. In most New Testament uses it means 'freely' or 'without charge,' as when Jesus tells his disciples to give freely what they freely received (Matt 10:8), or when Paul declares that believers are justified freely by God's grace (Rom 3:24). Spanish captures this well with 'gratis' and 'de balde.' At John 15:25, however, it shifts to mean 'without cause'--they hated me without reason--while at Galatians 2:21 it takes on the nuance 'for nothing, in vain,' rendered 'en vano' in Spanish.