[nut case] {n. phr.} A very silly, crazy, or foolish person. […]

[nutcase] {n.} An insane person.

[nuthouse] {n.} A lunatic asylum.

[nuts and bolts of] {n. phr.} The basic facts or important […]

[nutter] {n.} Insane person.

[odd jobs] {n. phr.} Work that is not steady or regular […]

[oddball] {n.}, {slang}, {informal} An eccentric person; one who doesn't act […]

[odds and ends] {n. phr.} Miscellaneous items; remnants. * /After the […]

[odds and sods] {n.} Substitute for '[odds and ends]'. Miscellaneous items […]

[off day] {n. phr.} A period when one is not functioning […]