/ˈpleɪshoʊldər/
place·hold·er
BrE /ˈpleɪshəʊldə(r)/
NAmE /ˈpleɪshoʊldər/
(specialist)
a symbol or piece of text which replaces sth that is missing
(linguistics)
an item which is necessary in a sentence, but does not have real meaning, for example the word ‘it’ in ‘It’s a pity she left.’