( ( ( base - ) ( ( a substance ) ( that ( produces ( ( hydroxide ions ) ( in ( aqueous solution ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NN base)) (: -) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (VBZ produces) (NP (NP (JJ hydroxide) (NNS ions)) (PP (IN in) (NP (JJ aqueous) (NN solution)))))))) (. .)))
base -a substance that produces hydroxide ions in aqueous solution.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN base)) (VP (VBZ is) (NP (NP (DT an) (JJ ionic) (NN compound)) (SBAR (WHNP (WDT that)) (S (VP (VBZ produces) (NP (JJ negative) (NN hydroxide) (NNS ions)) (SBAR (WHADVP (WRB when)) (S (VP (VBN dissolved) (PP (IN in) (NP (NN water)))))))))))))