1. Characterized by effort to the point of exhaustion; especially physical effort
   - arduous, backbreaking, grueling [US], gruelling [Brit, Cdn], hard, heavy, laborious, operose, punishing

See also: effortful, toilsomeness

• Fulbright
• fulcrum
• fulfil
• fulfill
• fulfilled
• fulfillment
• fulfilment
• fulgent
• fulgid
• Fulgoridae
• fulgurant
• fulgurate
• fulgurating
• fulgurite
• fulgurous
• Fulica
• Fulica americana
• Fulica atra
• fuliginous
• full
• full admiral
• full beam
• full board
• full complement
• full cousin