No matter how long we inhabit our native language, there are still moments when we perceive something we’d never noticed before. One day last month I used the word tidy, and suddenly a question came to mind: might it be the case, I asked myself, that in spite of an apparent semantic mismatch, tidy comes from tide in the same morphological way that juicy obviously comes from juice and flaky from flake? I felt I was onto something because I already knew that the current meaning of tide as ‘a periodic rising and falling of the sea’ is a limited survival of the much broader senses the word used to have: ‘time; period; season.’ For example, in 1596 Edmund Spenser wrote in “Prothalamion”:
They two, forth pacing to the river’s side,
Received those two fair brides, their love’s delight;
Which, at th’ appointed tide,
Each one did make his bride….
Tidy was indeed the adjective corresponding to tide in that early sense, and the original meaning of tidy was, in the definition of the 1913 Webster’s Revised Unabridged Dictionary: ‘Being in proper time; timely; seasonable; favorable; as, tidy weather.’ From that developed the senses ‘Arranged in good order; orderly; appropriate; neat; kept in proper and becoming neatness, or habitually keeping things so; as, a tidy lass; their dress is tidy; the apartments are well furnished and tidy.’
To make a connection to Spanish, we have to go much farther back than early modern English. The American Heritage Dictionary traces tide to the Indo-European root *dā- ‘to divide,’ which we can see in the old sense of ‘season,’ which is a division of the year. The AHD finds in the suffixed Indo-European form *dā-mo‑ the possible notion of ‘division of the people,’ as reflected in ancient Greek dēmos, which meant ‘people; land.’ From that we have borrowed words like democracia/democracy ‘rule by the people’; demagogo/demagogue ‘someone who stirs up the people’; and endémico/endemic ‘occurring in a certain region.’