Answer: stic

AnswerCrossword Clue
STICBic ... (pen brand)
STICBic Clic -- (pen brand)
STICGlue -- (adhesive-in-a-tube brand)
STICClic (Bic pen brand) --
STICBic Clic --
STICGlue -- (adhesive brand)
STICBic Round -- (pen brand)
STICBic Clic ... (writing brand)