tangential

Only slightly connected or relevant to what is being discussed; divergent.

• tangent/ˈtændʒənt/(n)切线/离题
• tangentially/tænˈdʒɛnʃəli/(adv)离题地

• tangential point
• tangentially related
• go off on a tangent
• tangential issue

1. 1.His comments were tangential to the main discussion. (barely relevant)
2. 2.She tends to go off on tangents during meetings. (noun: side topic)

• irrelevant/ɪˈrɛləvənt/— not related at all, stronger
• peripheral/pəˈrɪfərəl/— on the edge, not central
• incidental/ˌɪnsɪˈdɛntl/— happening as a side effect

from "tangent" — a line that barely touches a circle — only barely touching the topic