usefully
From LSJ
ἡ κέρκος τῇ ἀλώπεκι μαρτυρεῖ → you can tell a fox by its tail, small traits give the clue to the character of a person
English > Greek (Woodhouse)
adverb
P. and V. προὔργου, P. συμφόρως, χρησίμως, ὠφελίμως, συμφερόντως, λυσιτελούντως, εὐχρήστως, προὔργου, χρηστικῶς, ἐπιτηδείως.