ゆだん油断yudan
1.

A state of mind characterized by a relaxed attitude that leads to a lack of vigilance or attention, often resulting in the potential for unexpected problems or failures.

2.

The act of letting one’s guard down, which may bring about negative consequences, especially in situations that require constant awareness and caution.

3.

A detrimental tendency to become complacent or inattentive, particularly when one's circumstances seem secure or unthreatening, thereby inviting risks or errors.

Example:

私は油断していたことに気づいた。

ゆだんたいてき油断大敵yudantaiteki
1.

The state of being overly relaxed or careless is a significant danger, as it often leads to mistakes and adverse outcomes.

2.

A lack of vigilance is a formidable opponent, as it can often result in failures or unforeseen troubles.

ゆだん油断yudanなくnaku
1.

Being in a state of constant awareness and readiness, avoiding complacency or distraction.

2.

Maintaining caution and mindfulness in actions or surroundings, ensuring that one does not overlook potential threats or risks.

3.

Engaging in activities with focused attention, emphasizing the importance of perseverance and diligence to prevent unexpected outcomes.

4.

Acting with a sense of vigilance, always prepared for the unforeseen or the possibility of negative events occurring.