(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).
Be careful because there was a cooking oil spill here.Ten cuidado porque hubo un derrame de aceite de cocina aquí.
The recent oil spill in the gulf has caused great harm to the marine ecosystem.El reciente derrame de petróleo en el golfo ha causado grandes daños al ecosistema marino.
(f) means that a noun is feminine. Spanish nouns have a gender, which is either feminine (like la mujer or la luna) or masculine (like el hombre or el sol).
you're spilling the milkestás derramando la leche;you've spilled or spilt coffee on your shirtte ha caído café en la camisa;she spilled or spilt wine all over the tablederramó el vino por toda la mesa
he was spilling his juice all over the placehe had spilt coffee all over his jumper
to spill the beansdescubrir el pastel (informal);contarlo todo