Likewise means 'the same goes for this one'. Someone says 'lovely to meet you', you say 'Likewise', and one word has done the work of a whole sentence.
In writing it links two things that behave the same way: 'The office shuts at four; likewise the post room.' Recipes and instruction manuals lean on it — 'Season the beef. Likewise the onions.' As a spoken reply it is warm but a little reserved, a shade cooler than saying the whole thing back. It is one word, never 'like wise', and it belongs at the front of the clause or right after the subject rather than stranded at the end. And do not reach for it when you are simply adding a second item: 'I bought bread and likewise milk' sounds wrong, because nothing is behaving the same way there. That sentence wants also.
1adverblikewiseIn the same way; following the same pattern.
“Hold the brush loosely; likewise the pencil.”
synonyms: similarly
2adverbshortUsed as a short reply to say that the same is true of you.
“He said it had been a pleasure, and she answered likewise.”
3adverbadditionAlso; in addition, where the second thing does the same as the first.
“The contract was signed by the seller and likewise by the buyer.”
synonyms: also, too
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: similarly
Likewise was once three words: in like wise, meaning 'in a similar manner'. Wise there is the old English noun for a way or a manner — the same wise hiding inside otherwise. Middle English squeezed the phrase into one adverb, lykewise, and kept the sense exactly.
Middle English
lykewise
English, today
likewise
From Middle English lykewise, lykewyse, lyke wyse, lijk wise, a shortened form of Middle English in lik wise (“in like wise”); equivalent to like + wise. Compare with otherwise.
Etymology from Wiktionary, CC BY-SA