Definition of "shrewd"

Willie is very aware of this fact and lets Johnny Attell know that there is a fly in the ointment, and Johnny, who is a very shrewd article, has his chauffeur drive him to Bradford Street so he can change the kid's mind.

2003, Ron Ross, Bummy Davis vs. Murder, Inc, page 287

The most persistent tormentor was Alex Oxlade-Chamberlain, who scored a hat-trick in last month’s corresponding fixture in Iceland. His ability to run at defences is instantly striking, but it is his clever use of possession that has persuaded some shrewd judges that he is an even better prospect than Theo Walcott.

2011 November 10, Jeremy Wilson, “England Under 21 5 Iceland Under 21 0: match report”, in Telegraph‎

Portia:There are some shrewd contents in yon same paper,That steals the colours from Bassanio's cheek:Some dear friend dead; else nothing in the worldCould turn so much the constitutionOf any constant man. What, worse and worse!— […]

c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene ii]

They were wont to please the Fairies, that they might doe them no shrewd turnes, by sweeping clean the Hearth and setting by it […]

1687, John Aubrey, Remaines of Gentilisme and Judaisme, page 29

Leonato: By my troth, niece, thou wilt never get thee a husband, if thou be so shrewd of thy tongue.

1598–1599 (first performance), William Shakespeare, “Much Adoe about Nothing”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene i]