(m) means that a noun is masculine. Spanish nouns have a gender, which is either feminine (like la mujer or la luna) or masculine (like el hombre or el sol).
There have been some shock defeats in this championship. The mighty are falling left and right.Hubo derrotas sorprendentes en este campeonato. Los poderosos caen a diestra y siniestra.
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g. to run quickly, very tired).
I'm mighty glad to hear itme alegro muchísimo de saberlo;she's a mighty fine-looking womanes una mujer muy guapa;we were mighty worriedestábamos la mar de preocupados (informal)
it was mighty embarrassing
it's a mighty long way to SouthforkSouthfork está tremendamente lejos or está lejísimos
she did mighty well in her examsthey worked mighty hardshe's mighty pretty
plural noun
the mightylos poderosos
how the mighty have fallen!¡cómo han caído los poderosos!