This study looks at how terror attacks are rendered discursively meaningful on social media through the concurrent use and reiteration of terror hashtags, which were created following previous incidents of terror. The article focuses on 12 terror attacks in Europe in 2015-2017 and their relating hashtags on Twitter, to see how various combinations of these were reused and co-articulated in tweets posted in relation to subsequent attacks. Through social network analysis of co-occurring hashtags in about 3 million tweets, in combination with close readings of a smaller sample, this study aims to analyze both the networks of hashtags in relation to terror attacks as well as the discursive process of hashtag co-articulation. The study shows that the patterns by which attack hashtags are reused and co-articulated depend on both temporal and contextual differences.