adj

• (of an object) Rigid; hard to bend; inflexible.
  "“A tight little craft,” was Austin’s invariable comment on the matron;[…]. ¶ Near her wandered her husband, orientally bland, invariably affable, and from time to time squinting sideways, as usual, in the ever-renewed expectation that he might catch a glimpse of his stiff, retroussé moustache."
• (figurative, of policies and rules and their application and enforcement) Inflexible; rigid.
• (of a person) Formal in behavior; unrelaxed.
• (colloquial) Harsh, severe.
  "He was eventually caught, and given a stiff fine."

noun

• (slang, chiefly Canada, US) An average person, usually male, of no particular distinction, skill, or education.
  "working stiff"
• (slang) A person who is deceived, as a mark or pigeon in a swindle.
  "She convinced the stiff to go to her hotel room, where her henchman was waiting to rob him."
• (slang) A cadaver; a dead person.
  "This parrot is no more! It has ceased to be! It's expired and gone to meet its maker! This is a late parrot! It's a stiff! Bereft of life, it rests in peace! If you hadn't nailed it to the perch it would be pushing up the daisies!"
• (slang) A flop; a commercial failure.
  "If the movie was a stiff it wasn't any of their specific faults. They were all in it together and they were jobbed in and jobbed out for two weeks and gone and they got a pile of money for their efforts."

verb

• (slang) To kill.
  "But you know it could be a hassle / Trying to explain myself to a police officer / About how it was your old lady got herself stiffed"
• (informal) To be unsuccessful.
  ""Come To Me" moved but a few to buy a copy; "My Queen" stiffed in the stall."

adv

• (nautical) Of the wind, with great force; strongly.
  "At Feversham was a very High Tide in the Afternoon, tho' the Wind was Southerly, and blew very stiff, which the Seamen there wondered at."