fiber optics (US), fibre optics (UK)

fiber (US), fibre (UK)

optics (physics of light and vision)

speciality/specialty; subject of study; subject of expertise; area of interest; profession

(chiefly women's speech) first person singular pronoun: I, me

(polite) first-person singular pronoun: I, me

a personal or private matter / (by extension) selfishness

(formal) first-person singular pronoun: I, me

personal, private / secret

a personal or private matter / selfishness / privacy, secrecy / (women's speech, obsolete) a brother-in-law