Define $(i)$ force $(ii)$ dyne $(iii)$ newton.

(N/A) $(i)$ Force is an external push or pull that changes or tends to change the state of rest or uniform motion of a body in a straight line.
$(ii)$ Dyne is the absolute unit of force in the $CGS$ system. One dyne is defined as the force that produces an acceleration of $1 \ cm \ s^{-2}$ when acting on a body of mass $1 \ g$.
$(iii)$ Newton is the absolute unit of force in the $SI$ system. One newton is defined as the force that produces an acceleration of $1 \ m \ s^{-2}$ when acting on a body of mass $1 \ kg$.