Phase - fays (''pl. of fay'')
From Hull AWE
- Fays is the plural of fay, an obsolete form of 'fairy', reflecting the French form fée.
- Phase is primarily a noun meaning 'a stage', or 'an item in a [repeated] cycle'. The moon has phases - new, quarter and full, for example; children go through phases (for example of naughty behaviour) while they are growing up. Gardens have phases of growth through the year. the verb 'to phase', which is transitive, means 'to introduce something in stages'.
- You may also want to see AWE's page on the commoner confusion, these days, between fazed and phased.