Yeah, slang typically originates from expressions that are in everyday use among significant subcultural population. ‘Washed up’ could’ve been related to the sea if it were coined in the mid-nineteenth century at the latest, when seaside occupations were still dominant in the economy, especially in the UK. But it’s too far-fetched for the twentieth century, when urban life became more important.
It makes the meaning more unclear. “Washed up” refers to washing up on the shore, i.e., being removed from the ocean. “Washed” means…you’re clean?
EDIT: I’m wrong, see below
Etymonline says that ‘washed-up’ is from theatre slang.
I stand corrected! Just saying “washed” is much closer to the original origin than I thought, then.
Yeah, slang typically originates from expressions that are in everyday use among significant subcultural population. ‘Washed up’ could’ve been related to the sea if it were coined in the mid-nineteenth century at the latest, when seaside occupations were still dominant in the economy, especially in the UK. But it’s too far-fetched for the twentieth century, when urban life became more important.