Found in Middle English and meaning ‘expert, skilful, clever’, hend comes from the word for ‘hand’, and originally meant ‘near at hand’. In a similar line are the words well-handed and habile.
And, indeed, handsome also relates to ‘hand’. Although chiefly used now to denote good looks, the adjective originally meant ‘easy to handle or control’, in the 15th century, and in the 16th century developed the sense of ‘clever’ (used of either a person or an action) around the same time that its most common current sense emerged.
The hand clearly has plenty of involvement with the mind, as dextrous is another historical synonym for ‘clever’ that stems from the hand – in this case from the Latin dextra, ‘the right hand’. This root is also seen in ambidextrous, meaning ‘able to use the right and left hands equally well’, from the Latin ambidexter, ‘right-handed on both sides’. Indeed, ambidextrous and two-handed both also appear in the Historical Thesaurus of the OED as synonyms for clever (in the sense of ‘skilful’).
From the Old French apert and thus the Latin apertum (meaning ‘open’), most senses of the adjective apert relate to different senses of open (from ‘unconcealed’ and ‘evident’ to ‘outspoken’ and ‘straightforward’). There is also, however, evidence that apert was used in Middle English to mean ‘distinguished, clever, ready, expert’. A possible explanation for this variant meaning is suggested by the OED etymology note that ‘in Old French the word was to some extent confused with aspert = espert < Latin expertus, ‘expert’, which seems to have affected some of the senses’.
Although now most commonly used to mean ‘anxious or fearful that something bad will happen’, the Latin root of apprehensive means ‘to seize’. This is seen more clearly in modern English in the verb apprehend – to arrest someone or to understand something (i.e. to physically or mentally apprehend, respectively) – and, similarly, apprehensive was once used to mean ‘capable of grasping with the mind; quick to learn, intelligent’. An early example can be found in Shakespeare’s Julius Caesar: ‘And men are flesh and blood, and apprehensive’.
Solert (and solertic) are both obsolete synonyms for clever, from the Latin sōlert-, which (in turn) comes from sollus (whole, entire) and ars (art). They are found in 17th-century sources, as are the related nouns solerty and solertiousness.
Currently the only example of the obsolete word smeigh, the adverb smeighly, and the noun smeighness are found in different sections of manuscripts from Trinity College, Cambridge. The words are related to Old English sméagan, meaning ‘to consider’.
Inept is famously an English word which sounds as though it should have an opposite but does not – although, in fact, it does. While inept is found in the early 17th century, from the Latin ineptus (unsuited, absurd, foolish), the back-formation ept (adroit, appropriate, effective) dates to the early 20th century. The OED’s current earliest evidence for ept is found in a letter written by E.B. White. The Latin ineptus is formed as an opposite of aptus, which is the root of modern English apt (appropriate or suitable; also, quick to learn).
Source: Oxford Dictionaries