### Clue: Stainer numbers tackled by male alto (5)
### Answer: HENNA 
 ### Explanation: Definition: Stainer
  N,N(2 abbrevs. for $$n$$umber) **contained in**(tackled by) [HE(pronoun for a male) + A(abbrev. for alto)].
Answer:  A reddish-orange dye,stainer for hair, skin, fingernails, leather and wool, from the henna plant.