slow to learn or understand; lacking intellectual acuity; "so dense he never understands anything I say to him"; "never met anyone quite so dim"; "although dull at classical learning, at mathematics he was uncommonly quick"- Thackeray; "dumb officials make some really dumb decisions"; "he was either normally stupid or being deliberately obtuse"; "worked with the slow students"
having high relative density or specific gravity; "dense as lead"
hard to pass through because of dense growth; "dense vegetation"; "thick woods"
permitting little if any light to pass through because of denseness of matter; "dense smoke"; "heavy fog"; "impenetrable gloom"
a friendly understanding between political powers
an informal alliance between countries
with firmness; "held hard to the railing"
earnestly or intently; "thought hard about it"; "stared hard at the accused"
with pain or distress or bitterness; "he took the rejection very hard"
very near or close in space or time; "it stands hard by the railroad tracks"; "they were hard on his heels"; "a strike followed hard upon the plant's opening"
into a solid condition; "concrete that sets hard within a few hours"
not easy; requiring great physical or mental effort to accomplish or comprehend or endure; "a difficult task"; "nesting places on the cliffs are difficult of access"; "difficult times"; "why is it so hard for you to keep a secret?"
indulging excessively; "he drank heavily"
characterized by effort to the point of exhaustion; especially physical effort; "worked their arduous way up the mining valley"; "a grueling campaign"; "hard labor"; "heavy work"; "heavy going"; "spent many laborious hours on the project"
characterized by good substantial quality; "solid comfort"; "a solid base hit"
matter that is solid at room temperature and pressure
not soft or yielding to pressure; "a firm mattress"; "the snow was firm underfoot"; "solid ground"
of one substance or character throughout; "solid gold"; "carved out of solid rock"
of the same color throughout; "solid color"
meriting respect or esteem; "an upstanding member of the community"
of a substantial character and not frivolous or superficial; "work of solid scholarship"; "based on solid facts"
of definite shape and volume; firm; neither liquid nor gaseous; "ice is water in the solid state"
entirely of one substance with no holes inside; "a solid block of wood"
financially sound; "the bank is solid and will survive this attack"
of good quality and condition; solidly built; "a solid foundation"; "several substantial timber buildings"
a written agreement between two states or sovereigns