ˈ ̷ ̷ˌ ̷ ̷ adverb
Etymology: Middle English, from forth (I) + with
1. : with dispatch : without delay : within a reasonable time
you are to proceed forthwith to your home
: immediately
2. : immediately after some preceding event : thereupon
when students … are suspended, they must forthwith leave Williamsburg — College of William & Mary Catalog
the legislature left the capital and that city forthwith became less important to the revolutionary forces
immediately there fell from his eyes as it had been scales: and he received sight forthwith — Acts 9:18 (Authorized Version)