1. [mid-19C+] full, complete, entire, esp. of time, e.g. a solid month.
2. [late 19C+] trusted; usu. as solid with.
3. [late 19C+] (orig. jazz) trustworthy, dependable, exciting, outstanding.
4. [late 19C-1900s] as solid on, solid for, devoted to.
5. [late 19C+] definite.
6. [late 19C-1950s] (US) secure, free of problems.
7. [1940s–60s] (Aus./N.Z.) severe, difficult, unfair, unreasonable.
see under con n.1
[late 19C] (US Und.) a woman’s long-term male lover (as opposed to any transient entanglements).
1. an admirable person, esp. a jazz or swing musician.
2. a real, genuine, amazing thing.
SE in slang uses
[1910s–30s] (US) stupid; also as n., a stupid person.
[late 19C] (US short order) an apple dumpling.