Fortis and lenis
In linguistics, fortis ( FOR-tiss; Latin for 'strong') and lenis ( , LEE-niss, LEN-iss; Latin for 'weak'), sometimes identified with 'tense' and 'lax', are pronunciations of consonants with relatively greater and lesser energy, respectively. English has fortis consonants, such as the p in pat, with a corresponding lenis consonant, such as the b in bat.