P. and V. εὐθύμως (Xen.), ἡδέως, P. ἱλαρῶς (Xen.).
zealously: P. and V. προθύμως.
willingly: P. and V. ἡδέως, or use adj., P. and V. ἄσμενος, ἑκών.
bear cheerfully: P. and V. ῥᾳδίως φέρω, ῥᾳδίως φέρειν (acc.).