Assuming all words are simple REs (no metacharacters):
proc findAllWords {wordList text} {
set start 0
while {[llength $wordList]} {
set RE [join $wordList |]
if {![regexp -start $start -indices $RE $text range]} {
return 0
}
set word [eval [list string range $text] $range]
set idx [lsearch -exact $wordList $word]
set wordList [lreplace $wordList $idx $idx]
set start [expr {[lindex $range 1]+1}]
}
return 1
}