orthogonal
= O =
OS/2
OS /O-S/
1. [Operating System] n. An abbreviation heavily
used in email, occasionally in speech. 2. n. obs. On ITS, an
output spy. See "OS and JEDGAR" in Appendix A.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.