Nasal consonant

A nasal is a sound produced when the air is allowed to escape through the nose, while its oral passage may be blocked by the lips or tongue (a nasal stop) or opened (a nasal vowel). Nasal stops are often called simply "nasals".

Here are some nasal consonants:

[m] is a voiced, bilabial nasal
[ɱ] is a voiced labiodental nasal (SAMPA [F])
[n] is an alveolar or dental nasal
[ɳ] voiced retroflex nasal, common in Indic languages
[ɲ] voiced palatal nasal (SAMPA [J]); is an usual sound in European languages as in: Spanish �; or French and Italian gn; or Catalan and Hungarian ny; or Portuguese nh.
[ŋ] voiced velar nasal (SAMPA [N]), as in sing.
[ɴ] voiced uvular nasal

English, German and Cantonese have [m], [n] and [ŋ]

French has [m], [n] and [ɲ]

Catalan and Italian have [m], [n], [ɲ] as phonemes, and [ŋ] as an allophone.

Spanish has [m], [n], [ɲ] as phonemes, and [ɱ] and [ŋ] as allophones.

French and Portuguese have nasal vowels. In IPA, nasal vowels are indicated by placing a tilde (~) over the vowel in question. So French sang = /sã/.

See: phonetics, stop, fricative, affricate, approximant, International Phonetic Alphabet.