Longitudinal stability
The tendency for an aircraft nose to pitch up or pitch down, rotating around the lateral axis (wingtip to wingtip).
Also defined in 2 more sources
Stability of an aircraft along its longitudinal axis and about its lateral axis. Longitudinal stability is also called pitch stability.
Aviation Maintenance Technician Handbook — Airframe, p. G-21
Stability about the lateral axis. A desirable characteristic of an airplane whereby it tends to return to its trimmed angle of attack after displacement.