This comparative adjective means 'better' or 'more excellent,' describing what is superior or more advantageous. Paul uses the adverbial form in 2 Timothy 1:18: 'May the Lord grant him to find mercy from the Lord on that Day—and you well know (βέλτιον οἶδας) all the service he rendered at Ephesus.' The term conveys 'very well' or 'better than I can say'—Paul defers to Timothy's firsthand knowledge of Onesiphorus's ministry. Classical usage often appears in ethical contexts ('becoming better,' 'advancing'). Paul's usage is affectionate: Timothy knows better than anyone the extent of Onesiphorus's devoted service, which will be rewarded on the Day of Judgment.