I guess it's the game of tag ("tag, you're it!"). In Dutch it is called tikkertje ("tikkie, je bent 'm!"); as Old English and Old Dutch were very similar, this

I guess it's the game of tag ("tag, you're it!"). In Dutch it is called tikkertje ("tikkie, je bent 'm!"); as Old English and Old Dutch were very similar, this may explain the -i- in tig, or at least it made it easier for me to recognize the word. :-)