Townsend, 19, spent the first half of this campaign on loan with Ipswich and marked his full Spurs debut with a goal in the FA Cup win over Charlton earlier this month.
He goes straight into the squad to face Cardiff in the npower Championship this weekend and Spurs have installed a 24-hour recall clause into the deal.
Teenage kicks: Andros Townsend joins Watford on loan for the rest of the season
Explore more:Places: Cardiff
Source: Daily Mail
Source: Daily Mail