'carefully-checked' originates from the combination of 'carefully' and 'checked', where 'carefully' is derived from 'care' meaning 'attention' and '-fully' indicating 'in a manner of'. 'Checked' comes from 'check', meaning 'to examine'.

'carefully' evolved from the Old English 'caru' meaning 'sorrow, anxiety', and 'checked' from the Old French 'eschequier', meaning 'to stop'.

Initially, 'carefully' meant 'with sorrow or anxiety', but over time it evolved to mean 'with attention to detail'. 'Checked' has maintained its meaning of 'examined'.