ACROSS
 1. <suit> SPADES = _ES_ after SPA D
 5. MED IE ←LAV← = MEDIEVAL <in the Middle Ages>
 9. SPOONER* outside I = POISONER <criminal>
10. <annoyed> SHIRTY = HISTORY* without O_
11. <lawyer's bar> INJUNCTION = IN JUNCTION
13. "ROE TEA" = ROTI <bread>
14. <Greek characters> PSIS = "SIZE"
15. <calculation> ARITHMETIC = (CRIME THAT I)*
16. MI LIT I AMEN = MILITIAMEN <emergency troops>
19. B_ + LIP = BLIP <small hiccup>
20. <disguise> CAMO = CAM + O
21. MO NOSE + X U A_ L_ = MONOSEXUAL <into only one gender>
22. _W (ID EST) = WIDEST <furthest from the target>
23. LOTH [-m]ARIO = LOTHARIO <rake>
25. <natural> UNFORCED = (DECOR FUN)*
26. <bearish> URSINE = (.e)UR'S INE(x.)

DOWN
 2. ←(.a)NOI TACIT SONG OR P(o.)← = PROGNOSTICATION <predicting the future>
 3. <talk about> DISCUSS = S after DISCUS
 4. SUNT _Z_U_ = SUN TZU <philosopher-general>
 5. "MA + TEENY" = MARTINI <cocktail>
 6. <turns off> DISENCHANTS = _D SINCE* HANTS
 7. <woman who left> EMIGREE = E + REGIME*
 8. <Christian rebel> ANTITRINITARIAN = TRAIN*£*
12. <likeable> CHARISMATIC = CHAR IS MAT I C_
17. (IN ON) EG _O_ = IN ONE GO <simultaneously>
18. <did consort> MINGLED = MING-LED
19. <result of twelve> BOXCARS = BOARS outside XC
24. See 4 Down