- Opt Verb
- Opt in Verb
- Opt out Verb
- Optant Noun
- Optate Verb
- Optation Noun
- Optative Adj Noun
- Opthalmic
- Optic Adj Noun
- Optical Adj
- Optically Adv
- Optician Noun
- Opticist Noun
- Opticity Noun
- Opticochiasmal Adj
- Opticochiasmatic Adj
- Opticociliary Adj
- Opticoencephalitis Noun
- Opticofacial Adj
- Opticohemiplegic Adj
- Opticospectral Adj
- Optimal Adj
- Optimality Noun
- Optimally Adv
- Optimate Noun Adj
- Optimeter Noun
- Optimisation Noun
- Optimise Verb
- Optimised Adj
- Optimism Noun
- Optimist Noun
- Optimistic Adj
- Optimistical Adj
- Optimistically Adv
- Optimization Noun
- Optimize Verb
- Optimized Adj
- Optimizer Noun
- Optimum Adj Noun
- Option Noun
- Optional Adj
- Optionality Noun
- Optionally Adv
- Optionee Noun
- Optioner Noun
- Optionor Noun
- Optoacoustic Adj
- Optocoupler Noun
- Optoelecronic
- Optoelectronic Adj
- Optoelectronics Noun
- Optogalvanic Adj
- Optogram Noun
- Optoisolation Noun
- Optoisolator Noun
- Optokinetic Adj
- Optomechanical Adj
- Optometer Noun
- Optometric Adj
- Optometrical Adj