This book offers an original treatment of the lexical form look. The work is innovative in that it establishes that the Columbia School conception of an invariant meaning - hitherto found primarily in grammar - is equally operative in core vocabulary items like look and see. The upshot is that grammar and lexicon are both amenable to synchronic monosemic analysis. The invariant meaning proposed for look explains the full range of its distribution, without the need to posit as linguistic units 'look-noun' and 'look-verb', 'look-visual' and 'look-intellectual', or constructions such as have-a-look, look-like, etc. The analysis places look in opposition with see, seem and appear for which tentative meanings are posited as well. The hypotheses are supported through qualitative analyses of attested examples and quantitative predictions tested in a massive corpus. These predictions offer new knowledge about the distribution of look, see and other forms that may provide useful for other scholars.