Provided are liquid crystal compounds satisfying at least one of physical properties such as high stability to heat or light, a high clearing point (or high maximum temperature), low minimum temperature of a liquid crystal phase, small viscosity, large optical anisotropy, large negative dielectric anisotropy, a suitable elastic constant and good compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. The compound is represented by formula (1): wherein R1 and R2 are independently hydrogen or alkyl having 1 to 15 carbons; and A1, A2 and A3 are independently 1,4-cyclohexylene or 1,4-phenylene; Z1, Z2 and Z3 are independently a single bond; Y1, Y2, Y3 and Y4 are independently hydrogen, fluorine or the like; and a, b and c are independently 0 or 1, and a sum of a, b and c is 0 to 3.