烟酸

niacin (vitamin B3) / 3-Pyridinecarboxylic acid C6H5NO2 / nicotinic acid

cigarette or pipe tobacco / CL:根[gen1] / smoke / mist / vapour / CL:縷|缕[lü3] / tobacco plant / (of the eyes) to be irritated by smoke

sour / tart / sick at heart / grieved / sore / aching / pedantic / impractical / to make sarcastic remarks about sb / an acid