straight up

Short definition from Wiktionary

Adverb

1. 1
   Truthfully; honestly.
2. 2
   Unambiguously; bluntly; plainly and directly.
3. 3
   To the utmost degree; really.
4. 4
   Of an alcoholic drink, chilled, (stirred or shaken over ice) and served in a cocktail glass, with no ice.
5. 5
   Alternative form of straight up.

Adjective

1. 1
   Open, frank.
2. 2
   Alternative form of straight-up.
3. 3
   True; unambiguous; unqualified; plainly so, with no bones about it.
4. 4
   Of an alcoholic drink: served straight up.