Mucho is the 44th most common word in the Spanish language.
For English speakers mucho does not cause many problems. In fact, mucho does what lots of English speakers want to happen all of the time if you cannot think of the Spanish word – take an English word and “lob” an “o” on the end.
Mucho is an adjective and an adverb. My Collins Spanish – English dictionary runs to some 7 or so definitions. But given its similarity to the English word “much”, its translation does not really cause much (!) difficulty.
The translation comes down to “a lot” or, of course, much.
Here is a simple example of the use of mucho.
Tengo mucho trabajo – I have a lot of work.
Much to do about nothing then! – Mucho the forty fourth most frequently used word in the Spanish language.