Real Dictionary

solid-state
Solid-state electronic equipment is made using transistors or silicon chips, instead of valves or other mechanical parts.

solid-state in American English
designating or of the branch of physics dealing with the fundamental properties of solids, as structure, binding forces, electrical, magnetic, and optical properties etc., and with their effects
adjective: designating or pertaining to electronic devices, as transistors or crystals, that can control current without the use of moving parts, heated filaments, or vacuum gaps

solid-state in British English
noun: (of an electronic device) activated by a semiconductor component in which current flow is through solid material rather than in a vacuum

solid-state in Electrical Engineering
adjective: A solid-state device or circuit is one that relies on semiconductors rather than mechanical or vacuum tube circuits.