King James Bible Dictionary

WATCHFUL, adjective Vigilant; attentive; careful to observe; observant; cautious. It has of before the thing to be regulated, as to be watchful of ones behavior; and against, before the thing to be avoided, as to be watchful against the growth of vicious habits.

WATCHFULLY, adverb Vigilantly; heedfully; with careful observation of the approach of evil, or attention to duty.

General references
Exodus 23:13; Exodus 34:12; Deuteronomy 4:9; Deuteronomy 4:23; Deuteronomy 11:16; Deuteronomy 12:13; Deuteronomy 27:9; Joshua 22:5; Deuteronomy 6:17; Joshua 23:11; 1 Kings 2:3; 1 Kings 8:25; 1 Kings 2:4; 2 Chronicles 19:7; Nehemiah 4:9; Job 36:18-21; Psalms 39:1; Psalms 102:7; Psalms 119:9; Psalms 141:3; Proverbs 4:23; Proverbs 4:25-26; Proverbs 8:34; Proverbs 16:17; Proverbs 28:26; Nahum 2:1; Habakkuk 2:1; Malachi 2:15; Matthew 6:1; Matthew 16:6; Matthew 18:10; Matthew 24:4; Matthew 25:13; Matthew 26:40-41; Mark 4:24; Luke 8:18; Mark 13:9-23; Mark 13:32-37; Matthew 24:42-51; Luke 21:8-36; Luke 11:35; Luke 12:15; Luke 12:35-40; Acts 20:28-31; Romans 11:21; Romans 13:11; 1 Corinthians 7:29-31; 1 Corinthians 9:27; 1 Corinthians 10:12; 1 Corinthians 11:28; 1 Corinthians 16:13; Galatians 6:1; Ephesians 5:15; Ephesians 6:18; Philippians 3:2; Philippians 4:5; Colossians 4:2; Colossians 4:17; 1 Thessalonians 5:4; 1 Thessalonians 5:6; 1 Thessalonians 5:21; 1 Timothy 4:16; 2 Timothy 4:5; Hebrews 2:1; Hebrews 3:12; Hebrews 12:15; 1 Peter 1:13; 1 Peter 1:17; 1 Peter 4:7; 1 Peter 5:8; 2 Peter 1:19; 2 Peter 3:17; 1 John 5:18; 2 John 1:8; Jude 1:20-21; Revelation 3:2-3; Revelation 3:11; Revelation 16:15
Temptation

WATCHFULNESS, noun

1. Vigilance; heedfulness; heed; suspicious attention; careful and diligent observation for the purpose of preventing or escaping danger, or of avoiding mistakes and misconduct.

2. Wakefulness; indisposition or inability to sleep.

WATCHFULNESS-often precedes too great sleepiness.