Forthwith/ˌfɔːrθˈwɪθ,ˌfɔːrθˈwɪð/ Definition 1 of 3Pro Tip 1/3Urgency Expressed Use 'forthwith' to show that an action needs to happen now, with a sense of urgency. Complete the task forthwith! Pro Tip 2/3Technical Tone 'Forthwith' adds a formal or technical tone to instructions or requests. Rectify the error forthwith. Pro Tip 3/3Modern Precision In modern usage, 'forthwith' implies precision and immediacy, often found in business or legal contexts. Report your findings forthwith.