"Poincaré transformation" is the name sometimes (e.g., Misner et al. 1973, p. 68) given to what other authors term an inhomogeneous Lorentz transformation (x')^μ = Λ^μ_ν x^ν + a^μ, where Λ^μ_ν is a Lorentz tensor.

Lorentz transformation | Poincaré group