1chalk 
/ˈtʃɑ:k/ noun
plural chalks /ˈtʃɑ:k/ noun 1 [noncount] : a type of soft, light-colored rock ◊Chalk is a kind of limestone. 2 a [noncount] : a substance that is made into white or colored sticks and used for writing or drawing
▪ The teacher handed her a piece of chalk and asked her to write the answer on the chalkboard. ▪ He put chalk marks on the stage to show the actors where they should stand. ▪ a chalk drawing [=a drawing done with chalk]
b [count] : a piece of chalk
▪ They drew pictures on the sidewalk with colored chalks.
▪ The teacher handed her a piece of chalk and asked her to write the answer on the chalkboard. ▪ He put chalk marks on the stage to show the actors where they should stand. ▪ a chalk drawing [=a drawing done with chalk]
b [count] : a piece of chalk
▪ They drew pictures on the sidewalk with colored chalks.
not by a long chalk
Brit : not at all
▪ Our work isn't done yet, not by a long chalk. [=(US) not by a long shot; we still have a lot more work to do]
▪ Our work isn't done yet, not by a long chalk. [=(US) not by a long shot; we still have a lot more work to do]
— chalky /ˈtʃɑ:ki/ adjective, chalk·i·er; chalk·i·est [also more chalky; most chalky]
▪ chalky white [=the color of white chalk] ▪ chalky soil [=soil that has chalk in it]
/ˈtʃɑ:ki/ adjective, chalk·i·er; chalk·i·est [also more chalky; most chalky] ▪ chalky white [=the color of white chalk] ▪ chalky soil [=soil that has chalk in it]
