Hey there,
Not sure I'm seeing the same SERPs as you...
Okay, for "terminology management" you rank 1st in the Uk https://www.google.co.uk/search?biw=1366&bih=683&q=terminology+management&gl=uk&pws=0
and #3 for "translation memory" https://www.google.co.uk/search?gl=uk&pws=0&q=translation+memory
Notice that I use 2 additional parameters in the search URL, pws=0 removes personalization and gl=uk tells Google I'm searching from the UK.
No offence to Maximillion here, but hreflang is not the right choice for you at the minute. If you start losing ground to UK based websites for these generic English terms, you can follow the previous advice but you'd have to make some really clever/complicated adjustments. From the current situation, you're in very good shape and you shouldn't need to do anything else.