8 letters · 16 points in Scrabble
originFrom twitch + -er. The birdwatching sense first recorded in 1970 and recalled as being in use in 1968; claimed by R.E. Emmett to have arisen in 1950s Britain in reference to birder Howard Medhurst who often arrived at rare‑bird sites shivering after riding pillion on Emmett's motorcycle.
Etymology from Wiktionary, CC BY-SA 3.0